Ok, sharing my experience in hopes it helps someone else. A few months back the truck (2005 Sequoia 4x4) threw codes P0418 and P1613. Did some research and the common guidance was to replace the air injection driver. Easy enough to replace myself but after doing so, the codes kept intermittently coming back even after clearing them with the scan tool and disconnecting the battery.
A month or so the truck threw codes P0031 and P0051. Repair manual said the common fix is to replace the 02 sensors (both upstream and downstream). Picked up Denso replacements and swapped them out but the damn codes came back a few days later.
I could smell the truck was running rich, cold start ups were not the normal smooth process, but when it threw a P0300, P2238, and P2241 (in addition to all the others) I really became concerned.
Brought it into the shop and they dove in peeling back the wire harness leading to the ECU. Working theory was the ECU was bad or a there was an electrical short somewhere. Ultimately, they found the ground wire feeding both the secondary air injection system and air/fuel sensors was the root of the problem. Unfortunately, the ground is buried in the valley of the engine next to the starter and SAIS pump. Rather than pull the top off the engine, they were able to create a new ground and voila, CEL light and codes went away.
The truck is running great and the whole experience truly hammered home the importance of a good electrical ground!
A month or so the truck threw codes P0031 and P0051. Repair manual said the common fix is to replace the 02 sensors (both upstream and downstream). Picked up Denso replacements and swapped them out but the damn codes came back a few days later.
I could smell the truck was running rich, cold start ups were not the normal smooth process, but when it threw a P0300, P2238, and P2241 (in addition to all the others) I really became concerned.
Brought it into the shop and they dove in peeling back the wire harness leading to the ECU. Working theory was the ECU was bad or a there was an electrical short somewhere. Ultimately, they found the ground wire feeding both the secondary air injection system and air/fuel sensors was the root of the problem. Unfortunately, the ground is buried in the valley of the engine next to the starter and SAIS pump. Rather than pull the top off the engine, they were able to create a new ground and voila, CEL light and codes went away.
The truck is running great and the whole experience truly hammered home the importance of a good electrical ground!
